Lisa,
Thanks for sharing. Never think what you are feeling is wrong. Our feelings belong to us and are real for us and that is why it is so important for us stepmoms to feel validated. Our husband doesn't have to agree with what we are feeling but when he validates our thoughts and emotions, we don't feel so alone.
The job of stepmom is not easy. One of the biggest challenges we face is all the relationships "we marry" when we say "I do" to a man with children. And while we inherit these relationships, the reality is that we don't have a lot of control over them.
The situation regarding the photos is a tough one. I can see how your feelings are hurt. Children, no matter how old they become, are fiercely loyal to their parents. Perhaps, your stepdaughters fear their mom would get upset if they post photos with you in them and they are being considerate of her (albeit at your the expense of your feelings).
And often extended family tries to keep the door open to the ex for the sake of the kids and they may not be considering how it will impact you.
I think it is great that you recognize what is causing you pain. I know it doesn't make it any easier but knowing why you are hurting helps you figure out ways to deal with it.
I'm glad you found our community. We are all walking this journey together and I truly feel it is a blessing to surround yourself with other positive minded Smoms.
Wishing you a peaceful day. Stay Strong and press on.
Heather